Hi i have a 1990 camaro i have been working on for about a year and a half. I started out with a 350 block and made it a 383 stroker. Its got all the goodies like full msd and everything is brand new. New radiator new hoses everything. I started out by going to a lower thermastat to see if that would help. had no luck there. thought maybe there could be a vapor pocket and that wasnt it. im stuck on it bc i cant drive it very far without it overheating. i have played and played with the timing. i had a friend tell me its in my timing and my cam. i have a 468 flat tappet cam with roller rockers. im lost. if someone could give me any suggestions it would be appreciated. thanks

What kind of radiator and cooling fans are you running? Also, what are you doing for a fan switch? The factory switch goes on at 210F I believe, much too hot.

im not sure what kind of radiator i have. i bought it from a local parts store. if i remember right its a 2 core radiator but the cores are 1 inch thick. and i am also running stock fans to a toggle switch so i control when they come on and off.

also another thing i forgot to add.......If i just turn my car on and let it idle its fine i could let it run all day and it wouldnt overheat. Its only when im out driving it. . . . .

Your rad might not be hefty enough for a 383. You might need a 3 or 4 core aluminum rad. Also, do you turn the fan off above 45mph? If you don't it actually messes with the natural flow of air.
Alex

Edit: check your air dam, if it's damaged you might not even be getting any air when moving.

yes airdam needs to be checked if you dont have one that would be a good part of the cause, also...

you have the fans wired properly right? to suck air into the engine bay for the regular fan

yeah i have my fans hooked up correctly. im goin to go purchase a 4 core aluminum radiator this weeks and see what happens. Also i did my exhaust myself and where it comes off the headers on the pasenger side it got crushed a little bit so im thinking that could also have something to do with it. im running 2.5 in pipe so.....im going to get the new radiator and get my exhaust done at a shop and we will see what happens.

i have a 400 in my firebird, had the same problem, what i did was pick up a 2 core aluminum plastic radiator, hooked an eletric fan to it by toggle switch, then i took my thermostate and cliped the middle out so it stayed open. allowed my anti-freeze to run faster and it has so far seemed to work great

I'd suggest drilling a 4-6 small holes in the perimeter on the thermostat. This way the thermostat won't have to open as far to achieve the same coolant flow, but your engine will still be kept at a constant temperature.